Gas Purifying Process and Device

A gas purifying process for removing trace constituents from a mixed gas containing a rare gas and nitrogen as main components and at least one of hydrogen, nitrogen and hydrogen reaction products, water vapor and nitrogen oxides as said trace constituents, comprising the steps of:

• a denitration step for converting the nitrogen oxides into nitrogen and water vapor by means of a catalytic denitration reaction in the presence of a reducing substance;
• an adsorbing step for removing water vapor and nitrogen and hydrogen reaction products from the mixed gas which has gone through said denitration step;
• a hydrogen oxidation step for converting the hydrogen present in the mixed gas which has gone through said adsorbing step into water vapor by means of a hydrogen oxidation catalytic reaction in the presence of oxygen;
• and
• a drying step for removing water vapor generated in said hydrogen oxidation step.

A gas purifying device for removing trace constituents from a mixed gas that includes a rare gas and nitrogen as main components, and at least one from among hydrogen, nitrogen and hydrogen reaction products, and water vapor as a trace constituent, said device provided with:

• an adsorbing device for removing water vapor and nitrogen and hydrogen reaction products using an adsorbent;
• an oxygenation device for adding oxygen to the mixed gas that is leaving said adsorbing device;
• a hydrogen oxidation device for converting the hydrogen in the mixed gas after the oxygen has been added to water vapor by causing a reaction with the oxygen using a hydrogen oxidation catalyst;
• and
• a drying device for removing the water vapor generated in said hydrogen oxidation device using an adsorbent.

A gas purifying device for removing trace constituents from admixed gas that includes a rare gas and nitrogen as main components, and at least one from among hydrogen, nitrogen and hydrogen reaction products, water vapor and nitrogen oxides as a trace constituent, said device provided with:

• a reducing substance adding device for adding ammonia or hydrogen to said mixed gas as a reducing substance;
• a denitration device for reacting the nitrogen oxides present in the mixed gas after addition of the reducing substance, with said reducing substance by means of a catalytic denitration reaction, and converting said nitrogen oxides to nitrogen and water vapor;
• an adsorbing device for removing water vapor and nitrogen and hydrogen reaction products in the mixed gas exiting from said denitration device using an adsorbent;
• an oxygenation device for adding oxygen to the mixed gas that is leaving said adsorbing device;
• a hydrogen oxidation device for converting the hydrogen in the mixed gas after the oxygen has been added to water vapor by causing a reaction with said oxygen using a hydrogen oxidation catalyst;
• and
• a drying device for removing the water vapor generated in said hydrogen oxidation device using an adsorbent.